7200
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 54
- Divisor Sum
- 25389
- Proper Divisor Sum (Aliquot Sum)
- 18189
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1920
- Möbius Function
- 0
- Radical
- 30
- Omega Function (Ω)
- 9
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 57
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- yes
- Achilles Number
- yes
- Perfect Power
- no
- Smooth Number
- yes
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Number of ways of writing n as a sum of 6 squares.at n=19A000141
- a(n) = n! * lcm({1, 2, ..., n+1}).at n=5A002397
- Pentagonal pyramidal numbers: a(n) = n^2*(n+1)/2.at n=24A002411
- Expansion of (theta_3(z)*theta_3(7z)+theta_2(z)*theta_2(7z))^3.at n=32A002653
- a(n) = binomial(n,floor(n/2))*(n+1)!.at n=5A002867
- Representation degeneracies for Ramond strings.at n=15A005305
- List of periods for game of Third One Lucky.at n=21A006018
- List of periods for game of Third One Lucky.at n=22A006018
- Some permutation of digits is a factorial number.at n=49A007926
- Some nontrivial permutation of digits is a factorial number.at n=42A007927
- Theta series of {D_6}* lattice.at n=38A008425
- Smallest positive number that can be written as sum of distinct Fibonacci numbers in n ways.at n=68A013583
- Even pentagonal pyramidal numbers.at n=18A015224
- a(n) = n*(23*n + 1)/2.at n=25A022281
- a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026692.at n=6A026992
- a(n) = n + (n+1)^2 + (n+2)^3.at n=17A027620
- Denominators of poly-Bernoulli numbers B_n^(k) with k=3.at n=5A027646
- a(n) = (1/2)*floor(n/2)*floor((n-1)/2)*floor((n-2)/2).at n=50A028724
- Theta series of 8-d 5-modular lattice Q_8(1) with det 625 and minimal norm 4.at n=9A028976
- Number of symmetrically inequivalent coincidence rotations of icosian ring of index n.at n=43A031366